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An Apache PDFBox fork intended to be used as PDF processor for Sejda and PDFsam related projects

There is a newer version: 3.0.21

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.sejda.sambox.cos;

import java.io.IOException;

/**
 * This class represents a null PDF object.
 *
 * @author Ben Litchfield
 */
public final class COSNull extends COSBase
{
    /**
     * The one null object in the system.
     */
    public static final COSNull NULL = new COSNull();

    private COSNull()
    {
        // limit creation to one instance.
    }

    @Override
    public void accept(COSVisitor visitor) throws IOException
    {
        visitor.visit(this);
    }

    @Override
    public String toString()
    {
        return "COSNull";
    }

    @Override
    public void idIfAbsent(IndirectCOSObjectIdentifier id)
    {
        // we don't store id for NULL. We write them as direct objects. Wrap this with an IndirectCOSObject if you
        // want to write a null as indirect reference
    }
}